Valtteri Bottas has topped the final Azerbaijan Grand Prix practice and team mate Lewis Hamilton finished third as Mercedes heaped pressure on Ferrari's Formula One championship leader Sebastian Vettel.
Bottas led qualifying and set an even quicker time on his final lap, only for Hamilton to beat him by almost half a second.
Bottas was the only auto to get within a second of Hamilton, as the Mercedes showed it is, without doubt, the fastest qualifying vehicle.
"Tomorrow is going to be a long hard race, but we are in the best position to start it".
"I wasn't quite comfortable with the tire temperature", said Bottas, who took pole at the Bahrain GP. "I hope I wasn't the only one going down the escape roads many times". Bottas remained at the summit of the timesheets for the majority of the session, setting an impressive time initially on the yellow-marked soft tyres which was beaten by almost a second when he switched onto the super-soft - finishing on a 1:42.742.
The German leads Hamilton by 12 points after seven races.
Lots of mistakes as well, with Carlos Sainz overrunning a corner.
"Now it's just a case of getting our heads together tonight to work out exactly how to extract that pace across the entire weekend".
He refused to blame that incident or a lack of running for Ferrari's failure to provide more of a threat to Mercedes in qualifying.
While Haas got one vehicle through to Q2 after a late lap from Magnussen, teammate Romain Grosjean's struggles under braking continued as he ailed to P17 ahead of Sauber's Marcus Ericsson.
Canadian teenager Lance Stroll of Montreal qualified eighth.
Already facing a combined grid drop of 75-places, McLaren-Honda drivers Fernando Alonso and Stoffel Vandoorne's struggles continued as they were both eliminated in Q1, finishing 16th and 19th respectively as they failed to make up for the power deficit of the Honda engine. The top ten comprised of Hamilton, Verstappen, Raikkonen, Ricciardo, Kvyat, Vettel, Bottas, Ocon, Perez and Massa.
Perez and Raikkonen then exchanged fastest times before Verstappen reclaimed the top spot, Hamilton however went even faster with a 1m42.384s.